Lymph node metastasis is a poor prognosis indicator in esophageal cancer. Although tumor spreading currently forms the main basis for therapy selection, the molecular mechanisms underlying the metastatic pathway remain insufficiently understood. Several studies aimed to investigate these mechanisms but focused mainly on regulatory patterns in the tumors themselves and/or the invaded lymph nodes. To date no study has yet investigated the potential changes on transcription level, which take place within the yet non-invaded niche. Here we provide a comprehensive description of these regulations in patients. In this study the transcriptomic profiles of regional lymph nodes were determined for two patient groups: patients classified as pN1 (metastasis) or pN0 (no metastasis) respectively. All investigated lymph nodes, also those from pN1 patients, were still free of metastasis. The gene expression data was obtained via microarray analysis. Top candidates were validated via PCR and immunohistochemistry. The results show that regional lymph nodes of pN1 patients differ decisively from those of pN0 patients even before metastasis has taken place. In the pN0 group distinct immune response patterns were observed. In contrast, lymph nodes of the pN1 group exhibited a clear profile of reduced immune response and reduced proliferation, but increased apoptosis, enhanced hypoplasia and morphological conversion processes. DKK1 was the most significant gene associated with the molecular mechanisms taking place in lymph nodes of patients suffering from metastasis (pN1). We assume that the two molecular profiles observed constitute two different stages of a progressive disease. Finally we suggest that DKK1 might play an important role within the mechanisms leading to lymph node metastasis.
Molecular changes in pre-metastatic lymph nodes of esophageal cancer patients.
Specimen part, Subject
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Low-grade and high-grade mammary carcinomas in WAP-T transgenic mice are independent entities distinguished by Met expression.
Specimen part, Disease stage, Time
View SamplesTransgenic expression in mice of two synergistically acting SV40 early region encoded proteins, large (LT) and small (sT) tumor antigens, in the mammary epithelium recapitulates loss of p53 and Rb function and deregulation of PP2A-controlled mitogenic pathways in human breast cancer. In primiparous mice, WAP-promoter driven expression of SV40 proteins induces well and poorly differentiated mammary adenocarcinomas. We performed a correlative aCGH and gene expression analysis of 25 monofocal tumors, representing four histopathological grades, to explore the molecular traits of SV40-induced mammary tumors and to emphasize the relevance of this tumor model for human breast tumorigenesis.
Low-grade and high-grade mammary carcinomas in WAP-T transgenic mice are independent entities distinguished by Met expression.
Specimen part, Disease stage
View SamplesTransgenic expression in mice of two synergistically acting SV40 early region encoded proteins, large (LT) and small (sT) tumor antigens, in the mammary epithelium recapitulates loss of p53 and Rb function and deregulation of PP2A-controlled mitogenic pathways in human breast cancer. In primiparous mice, WAP-promoter driven expression of SV40 proteins induces well and poorly differentiated mammary adenocarcinomas. We performed a correlative aCGH and gene expression analysis of 25 monofocal tumors, representing four histopathological grades, to explore the molecular traits of SV40-induced mammary tumors and to emphasize the relevance of this tumor model for human breast tumorigenesis.
Low-grade and high-grade mammary carcinomas in WAP-T transgenic mice are independent entities distinguished by Met expression.
Specimen part, Time
View SamplesPrecise nucleosome-positioning patterns at promoters are thought to be crucial for faithful transcriptional regulation. However, the mechanisms by which these patterns are established and dynamically maintained and subsequently contribute to transcriptional control are poorly understood. The Swi/Snf (Baf) chromatin remodeling complex is a master developmental regulator and tumor suppressor that is capable of mobilizing nucleosomes in biochemical assays. Yet, its role in establishing the nucleosome landscape in vivo is unclear. Here we have inactivated Snf5 and Brg1, core subunits of the mammalian Swi/Snf complex, to evaluate their effects on chromatin structure and transcription levels genome-wide. We find that inactivation of either subunit leads to disruptions of specific nucleosome patterning combined with a loss of overall nucleosome occupancy at a large number of promoters, regardless of their association with CpG islands. These rearrangements are accompanied by gene expression changes that promote cell proliferation. Collectively, these findings define a direct relationship between chromatin-remodeling complexes, chromatin structure, and transcriptional regulation.
Swi/Snf chromatin remodeling/tumor suppressor complex establishes nucleosome occupancy at target promoters.
Specimen part
View SamplesWe report high-throughput profiling of gene expression from whole zebrafish ventricles. We profile mRNA in uninjured ventricles and those undergoing regeneration 14 days after genetic ablation. This study provides a framework for understanding transcriptional changes during adult models of regeneration. Overall design: Examination of gene expression in cardiomyocytes under different states of proliferation.
Resolving Heart Regeneration by Replacement Histone Profiling.
No sample metadata fields
View SamplesIt is unclear how nanosecond electrical pulses affect gene expression.
Evaluation of the Genetic Response of U937 and Jurkat Cells to 10-Nanosecond Electrical Pulses (nsEP).
Specimen part, Cell line
View SamplesIt is unclear how nanosecond electrical pulses affect gene expression.
Evaluation of the Genetic Response of U937 and Jurkat Cells to 10-Nanosecond Electrical Pulses (nsEP).
Specimen part, Cell line
View SamplesmRNA expression levels were determined by NGS for wildtype larvae as well as for larvae lacking HP1a [Su(var)205^04/Su(var)205^05 transheterozygotes]. Overall design: RNA samples from wildtype (OR) and HP1a mutant third instar larvae were examined, using duplicate biological samples and Illumina NGS.
Enrichment of HP1a on Drosophila chromosome 4 genes creates an alternate chromatin structure critical for regulation in this heterochromatic domain.
Subject
View SamplesSMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1. Overall design: RNA-seq in six Smarcb1 deficient rhabdoid tumor cell lines, before and after Smarcb1 re-expression.
SMARCB1-mediated SWI/SNF complex function is essential for enhancer regulation.
No sample metadata fields
View Samples